The present invention relates to devices for injecting infusing, delivering, administering or dispensing a substance, and to methods of making and using such devices. More particularly, it relates to a device for administering a fluid product, such as a drug, therapeutic product, hormone, medicament, etc., into the body of a patient. In some embodiments, the device also serves to mix a product contained in an ampoule, e.g. a two-chamber ampoule.
A two-chamber ampoule and a corresponding injection device for administering and for mixing is known from DE 103 40 585 A1. For mixing, an ampoule holder which accommodates the two-chamber ampoule is moved into a casing of the injection device, wherein the user can grip a rear casing portion and a front portion of the ampoule holder and rotate them relative to each other, thus performing a mixing process.